Method and apparatus for shaping filaments.



I. W. IANVIER.

METHOD AND APPARATUS FOR .SHAPING FILAMENTS.

APPLICATION FILED JAN. 27 I914.

Patented Oct. 1 7, 1916.

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Ti FF or NEWARK, NEW JERSEY, ASSIGNOR TO eENEnAL'nLEc-rnm v COMPANY, ACORPORATION on NEW YORK. i

METHOD. AND APPARATUS FOR. SHAPING FILAMENTS.

Specification of Letters Patent.

PatentedOct. 17, 1916,

Application fi led January 27, 19151. Serial No. 814,616. Y

To all whom it may concern:

Be it'known' that I, J,OHN:W. .JANvrER, a citizen of the United States,residing at Newark, county of Essex, State of New Jersey Improyements inMethods and Apparatus for Shaping Filaments, of which the follow- -ingisa specification.

. My invention relates toa method of and apparatus for shaping andmounting metallic filaments, particularlyfilaments such as tungsten,which soften at operatingtemperatures, and are "mounteduponcomparatively small and resilient supports in the lamp, and isespecially applicable to metallic filament s made of comparativelyheavy" or stiff ends. Serious wire.

Metallic are usually given a winding "the wire filaments in'a continuouspiece looped or' zigaag form by back and forth over the supports onwhich 'it is carried in the lamp,

so that the shaping of the filament is an incident of the operation ofplacing it on the supports,

The filament maybe made of a Wire of suit-- able ductile material, suchas tungsten, wound ,back and forth in'one continuous piece supported atsuitable points intermediate its in winding the wire back and forth overits supports, and in making the loops uniform and properly mounted,particularly. Where the supports are comparatively small and resilientand the wireis heavy or stifi and hard to bend; 1 p

The object of my invention is to provide a method and apparatusfor-producing in a simple and easy manner filaments which are.

accurately shaped into a definite and predetermined form, and-Which areready to-be ther change in the form ofthe filament.

A further object is to enable the operator to makethe filament of theexact form and sizewhich it will be when mounted on its resilient orflexible. supports in the lamp.

"' A 'sti-ll'iuittherobject is to provide a 'method a'n'd means ofmaking a sinuous'or zigzag filament in'which the loops are ofluniformuand definite size, so that when'the filament'is mounted on thesupports every loop engages its support with substantially the sametension as every other loop.

In carrying out my invention I bend the have invented certain 'new' anduseful I while hot. j The loops of the filament may be elondifficultiesare encounteredfilament into a loop' or loops of approximately the formwhich it will be when loop of a definite and predetermined length.

after which the shaped filament. may be placed on its supports withbending or shaping. I prefer to elongate the loops'while the wire isheated in some suitable manner, as by the passage of current through it.If the wire, as for example, 'dragvn tungstemgis quite resilient, theheating not'only vfacilitates the operation of elongating the loops, butthe loops w 1ll set, and will retain when cool the shape lnto which theywere drawn gated to the desired extent in various suit able ways, but Ipreferto provide an-apparatus upon which the filament can be easily andquickly wound into approximately-nits finished form, and by which theloops can then be elongated to whatever extentlmay be necessary to bringthefilament into its finished form. Preferably thisapparatus is soconstructed that the operation of wind-J ing and, setting the filamentcan be accom- 1 plished very quickly and easily by' comparativelyunskilled labor, and the lengtheof the stretched loops may be regu'lated:very' accurately'. The apparatus is preferablyso constructed that itcan at will be 'placedinl a (su table atmosphere in which the filamentmay be heated to the desired extent without injury 1 U My invention willbest be understoodin connection with the accompanying drawing, in which,merely for purposes ofillustration, ll-have shown some of thevarious-forms in which my invention may be embodied, and in which- 1Figure 1 is aperspective view, with some parts in: section, of oneformof device suitable for practising my invention Fig. 2. is

a view, at right angles to the plane of Fig. 1,

of-the lower part of the device shownin Fig. 1 and with a part insection; and Fig. .3 is a r view of a modified formof the upper end ofthe device shownin Fig. 1. r

t In the particular apparatus or filament shaper shown in the drawing, asuitableisupport, such as a rod '1', has heads 2 and 3 slidably orotherwise suitably mounted on it so as to be relatively movable towardand away i of the lower head 3.

in engagenent with the stops land 5.

from each other. A stop I limits the movement of the upper head 2 and ifdesired a stop. 5 may be used to limit the movement The relativemovement of these heads may be produced in any suit able way. In thepreferred construction the heads 2 and 3 are biased in any suitablemanner so as to have a tendency to move away from each other and intonormal position, where they are a definite distance apart and Thistendency may be produced by the weight of the lower head 3, by a spring,or by any means which urges the heads away from each other. I prefer touse a spring, such as a spring 6, with one end rigidly supported, as forexample, by an adjustable abutment 7, and the other end exerting uponthe movable head 2 a thrust which tends to move this head away from theother one and -against the stop I.

I The wire of which the filament i's to be formed is secured to themm'ableheads 2 and 3 111 any suitable manner, while those heads'arecloser together than normal, after supports 10 mounted on and insulatedfrom it and also provided with hooks 11. The wire of which the filamentis to be formed is wound over the hooks 9 and 11 into approximately theform of the finished filament, but since the heads are closer togetherthan normal the loops are more open and shorter than when the filamentis finished. For purposes of illustration I have indicated a .wire 12which has been mounted upon the hooks and is ready to bedrawn into thefinished form by the movement of the heads 2 and 3 away from each otherinto normal relation. To facilitate ,tlie shaping of the filament Ipreferto heat 'the wire in some suitable way, preferably bypassingcurrent through it., One way of attaining this result is shown inthe drawing, in which binding posts 13 are provided, by means of whichthe ends of the wire may be firmly clamped to the head 3, and at thesame time an electrical connectiongi s'established to conductors or bars14:. t -which the binding posts 13are connected. rrent is supplied tothese conductorsthrong suitable terminals 15, which may be connected inany suitable manner we source of cur rent. As the hooks 9 and 11are-insulated, the application of voltage to the terminals I, with aconvenient operating handle, for

moving the head 2 against the. thrust of the spring (3 a definitedistance and to a sutlicient extent, as shown in Fig. 1, to facilitateeasy winding of the wire 12 over the hooks 9 and 11. I also prefer toprovide locking means, such as a set screw 17, by which the head 2 canbe firmly fixed in any desired relation to the other head, regardless ofthe .thrust exerted b the spring 6. I also prefer to provide somesuitable clamping means, such as the set screw 18, for at will holdingthe lower head 3 immovable.

The heads 2 and 3 may be biased to move away from each other by othermeans than the spring, as shown, in the modification illustrated in Fig.3. In this particular arrangement the head 2 is urged. upward intonormal position by the pull exerted upon it by a suitable weight 19connected to the head by a cord or cable 20 running over suitablepulleys. lVhen the cam 16 is thrown back into the position shown in Fig.1, the weight 19 will raise the head 2 the distance necessary to bringit against'the stop 4:.

The number of hooks on the heads may be varied as desired and theinvention is equally useful in making filaments consisting of only oneloop of heavy wire. In this case the two ends of the wire are securedance witl my invention, the heads 2 and 3 are movel toward each othertoa suitable extent, eitherby hand or by the use of the. cam 16. In eithercase I prefer, in a device constructed in accordance with Fig. 1, tocompressthe spring 6 so that the heads will have. a tendency to moveaway from-each other when released. Vhen the heads are properlypositioned closer together than normally, they are temporarily fixed bybeing clamped to the support 1 by means of the set screws 17 and 18. Oneend of the wire of which the filament is to be made is then clampedunder" one of the binding posts 13. The wire is then bent over one ofthe hooks 9,'carried back to the hook 11 adjacent to the binding post towhich the end was secured, back to another hook 9, and. so

into normal relation. This may bedone by naom'ss '1, looped into-theapproximate form of the finished filament, but the loops areconsiderably shorter and the bends are considerably more rounded than inthe finished filament. The filament is then brought into its final formby moving the heads away from each other a suit'able distance tobring-them unclamping the head 2 from the support 1, whereupon thethrust of the spring 6 moves .the. head 2 upward funtil it strikes-thestop 4. The filament isnow the correctshape andthe loops are of an exactand uniform length so that they can be putupon the resilient supportsvery easily and quickly The filament is. of the exact size andshapethatit willbe when in the lamp so that-nofurther manipulation whatever isrequired:

. The operation of shaping the filament is greatly facilitated byheating it to a suitable temperature. In shaping tungsten filaments, forexample, this heating-is carried out in an inert atmosphere, asforexample by inserting theshap'er with the wire upon it into asubstantially vertical flaskorjar open at the lower end and keptfilledwith a mixture of hydrogen and nitrogen, or other suitable ghs. Theoperator ean easily raise the shaper'into the'jar through the openlo'wer end, and then the wire is heated in any suitablemanner,-preferably by supplying current to: the terminals 15, whereupon.sulficient current flows from one terminal through the wire to the otherterminal to heat the wire and soften it so that the spring 6 movestheheadsaway from each other into normal-relation and the loops arestretched to the proper length. A' further advantage of heating the wireis that it is set and retains its shape when cool.- v By my invention aplurality of filaments of exactly the same dimensions and configurationInay be obtained. It may be employed with special advantage when anypart of the supporting means of the filament is too weak to stand thestrain that would be imposed upon it if the filament were wound over thesupport. It is applicable inconneetion with the manufacture of filaments'What I claim as new and desire to secure by Letters Patent ofthe UnitedStates, is

1. The method of. shaping a Wire into a I long filament having aplurality of loops of substantially equal and degnite length whichconsists, in bending the ire into loops of approximately the size ofthecorresponding loops of the finished filament, holding the ends of thewire and simultaneously moving the bends-of all-the loops into definiteand predetermined positions While holding the ends of the wire immovablebut permitting the intermediate portion to move lengthwise to equalizethe loops.

2. Themethod of shaping a long looped filament of tungsten whichconsists in bend-- inga tungsten wire into a plurality of loops eachshorter than the corresponding loop of the finished filame'nt,-heatingthe wire in an inert environment to render it pliable, and thenstretching all the loops'to definite dimensions lengthwise while holdingthe ends of the bent wire immovable but leaving the intermediate part.free to mov'eilengthe wise to equalize the loops.-

' 3. Apparatus for shaping filaments comprising relatively movablemembers for engaging a loop of wire near the ends of said loop and atthe bight, said-members being members to a definite and uniformdistance,

and .means for keeping the wire hot while said members separate.

4. Apparatus for-shaping a looped ,filament comprising a member forengagingthebight of a loop of-wire, another member for firmly engagingthe'sides of, the loop, said members being relatively movable at willtoward each other from normal position to engage a loop shorter thanthat of the finished filament, means for stopping said members in normalposition adefinite distance apart, and means for heating said wire tosoften it and thereby permit the return of said members to normalposition;

5. Apparatus for shaping a looped 'filament comprising a support, amember on said support for engaging a loop of wire near the ends of saidloop, a second member on said support for engaging the bight of theloop, said members being normally a definite distance apart and beingmovable toward each other at will, means tending to maintain saidmembers in normal relation and at, said distance apart, and means forheating the loop of wire while supported bysaid members.

6. Apparatus for shaping a looped-filament comprising a support, amember on said support for engaging a loop of wire near the ends of saidloop, a second memnormal position a definite distance from her on said.suppdrtQfor-engaging the bi 'ht;

of the loop, said :inember s,.-I being n'orma 1y a definitedistaneeiapar'it'fand"mounted to-be ing; two relatively movableinsulazted supmovable toward. each. othely; a spring strainedby movementof saldlmemhersto ward each other, and electrical connections forpassing current through the wire. bf the loopto heat it. I I

'7. Apparatus for shaping arl'oopedmetal lic filament comprising tworelativelynmbm able members foriengaging-a wireloo'p-at the bight and atpoints on the sidesbf the loop, means to prevent relative movement Oisaid wire and said supports; means for. heat ingthe wire on saidsupports,-"and,me'ans for moving said supports relatively to each otherwhile the filament is heated to elongate the loop a definite amount,

8. Filament shaping apparatus comprismg two relatively movable headsnormallya definite distance apart and biased when closer than normal tomove away from each other into normal position, means for se-. curing aloop of wire shorter than the loop of the finished filament to saidheads with the bight of the loop connected to one of said heads and thesides of the loop connected to the other head, and means forheating-said filament to a temperature which permits said heads to moveaway fromeach other automatically into normal position and therebyelongate the loop.to the size of the 1 finished filament. w

9. Apparatus for" shapinga looped filale ment comprising a centralsupport-inggcrod', two heads slidably mounted onjsaidrfod; and. biasedto move away from eaeh other. into each other, means on one ofrsaidheads, -for engaging thebight ofaloop or wire, means on the" otherof said."headsfor-rigidly attaching the ends of theloop thereto, and

means for supplyingcurrent to the filament on said heads to heat it andthereby permit said heads to move away; from each other" into normalposition and .elongatethe loop to .a definite'lengt'h.

10 Filament shaping apparatus comprisports mounted to move relat1vely toeach other, means for securing a' looped filament. onqsa d supportswith} one of said su ppotgts' in engagementwit-h the bight ofthei aspring normally tending to move said-supports away from each other intonormaL-positio'n, restraining means for holdinglone of said supportsimmovable against the. force exerted by saidspring while said filament1s being placed in position and "for releasing,

saidsupport to permit said spring to move' it'to a definite pointand'therebystretch the loop of the filament to a' definite length.-

. 11.. a device for shaping a loo'ped'fila' ment, the combination of asupport, two

heads :slidably mounted on said sirppofrt -to move relatively to, eachother; astopfior engaging'on e of said heads tos-limit-its move mentaway from the other, aispring forno'rnally holding said head againstis'aid'} stop,

, an insulated support J on one of'said heads for engaging the 'bight,of'ag-loop oliwire,1 binding posts on'. the other head forllclampingfthe ends of said loop'to. said other head and supplying currenttothe loop, and a manually controlled camforholding said firstmelitionedheadjawayfirom the'stop to permiti'placing on 'said'heads a loop shorterthan that oi the finished filament and for re- 'leags ing fsaidlhead}atwill top'ermit said to theilength 'ofi a" loop. of the finishedfilameriv, v

In witness iwh'ereofgfl have hereunto set hand this 23d day ofi January,1914.

S NJVHITEHEAD, J H. ELKINS. 7

spring toim'ove said head into engagement "with saids'topfand therebystretch the loop

